Life-Cycle and Hygrothermal Based Optimization of Insulation Filled Masonry Blocks

Abstract

Fired clay masonry blocks are one of the most common building elements in Europe to construct thermal envelopes of buildings. However, due to current energy performance requirements, thermal insulation of buildings has become inevitable. Brick producers, therefore, started to develop their products and, as a possible solution, they come up with thermal insulation filled masonry blocks, which meet the energy performance requirements without the need of additional external insulation. However, there is still considerable potential left in the available range of these bricks to improve their hygrothermal performance. In our research, we connected building physical simulations with life-cycle assessment through a gradient-free geometry optimization method (COBYLA) to obtain better masonry blocks. We performed heat and moisture transfer (HAM) simulations while optimizing the internal geometry of the blocks within the given constraints regarding to manufacturability, and minimized heat losses as well as 50-year CO2 emission as objectives in the process. We tested the optimization process with mineral wool filled blocks and considered Hungarian climate. The main achievement of the research is that we found new internal geometry designs for insulation filled masonry blocks, which have significantly less thermal transmittance and lower global warming potential of the assumed 50 years of service life than the reference design, while also could be manufactured in current production lines as well.